The invention relates to a harvester adapter with stalk shredder for harvesting grain crops, particularly sunflower, comprising a frame structure attached to a combine harvester, at least two crop gathering units having a snout, the crop gathering units being secured to the frame structure, where neighbouring crop gathering units are arranged such that a channel with an open leading end is formed between them, and where a stalk gathering unit is disposed in driving connection with a harvesting mechanism on at least one side of the channels, and further comprising a collecting auger disposed rearward from the harvesting mechanism and at least one stalk shredder unit attached to the frame structure.
Grain crops, such as sunflower or corn are usually harvested with combine harvesters equipped with adapters (or, to use a more widespread term, “headers”). The adapters or headers have stalk guiding means adapted for guiding the stalks to a harvester unit comprising reciprocating or rotating cutting means. A crop conveying means adapted for conveying the gathered crops to the harvester through a throat is connected to the cutting means. Such adapters are disclosed among others in patent descriptions HU 220 027 and HU 184 307.
Seeds easily drop from mature grain heads of many grain crops, particularly sunflower. This may adversely affect grain losses, particularly if crops to be harvested are down or are entangled. Under favourable circumstances, grain loss is as low as 5-6% but it can easily increase to 10-20%.
A number of solutions have been proposed to reduce grain loss. According to Hungarian patent HU 178 941 seeds dropped inside the harvester machine are gathered by a rearwardly sloping envelope extending along both sides of crop rows. For harvesting short-stalk and/or down crops the adapter has to be lowered. In this position the slope of the envelope becomes insufficient for urging dropped grains towards the rear of the envelope.
A row-type harvesting machine is disclosed in patent description HU 211 802. The machine of the invention has snouts arranged corresponding to the row spacing, extending along both sides of rows. The snouts are rotatable about a hinge point and are connected to a vibrated envelope attached to a frame structure. An active stalk guiding mechanism and a harvesting mechanism are disposed under the vibrated envelope, with one or more one grain collecting means being disposed rearward from them. The stalk guiding mechanism extends into an open leading-end channel formed between the portions of the vibrated envelope. The stalk guiding mechanism is implemented utilizing guide chains. The harvesting machine according to the invention is suitable for harvesting down crops or short-stalk crops with minimal grain loss. A disadvantage of the design is that it cannot exploit the full potential of the harvester machine because the speed of the harvester is limited by the constant speed of the stalk guiding and harvesting units.
In sunflower fields harvested with headers conventionally applied a stubble with a height of 50-100 cm remains after harvesting is completed. The stubble is usually processed in a separate step using stalk shredder machines. The multiple-step harvesting process is time consuming and requires an extremely high amount of energy.
A known art solution is the sunflower harvesting adapter NAS 676 made by OPTIGÉP Kft. (www.optigep.hu). Apart from stalk gathering and harvester units this adapter also comprises stalk shredder units mounted on its frame structure. The stalk shredder unit consists of rotors driven through roller chains from two sides. The rotors are disposed on a common beam with a spacing corresponding to the row spacing. Because of its mounting height the adapter has a relatively large ground clearance and therefore it is disadvantageously incapable of harvesting down crops and crops having stalks lower than 1 m.